New Zealand Vintage Computer Forums

I bought another Commodore 64 on Trademe a few weeks back, a Commodore 64C in 'untested' condition. I was fair game for a fixer upper, so I bid anyway and got it for 20-something bucks. Well, it arrived this afternoon. I thought I'd be brave and give it a test fire straight away on the off chance it actually was a runner. Power LED works and the 1541 initializes, but not a heck of a lot else going on. I was thinking VIC problems...



So there she is. Fairly innocent looking, a bit rough and abused like it's 20-something years old. No worries so far.



Hmmm, why is there... rust marks around the power jack?



Oh lord...



My stomach was churning a little by now.



Well bollocks. Judging by the amazing amount of debris and corrosion, this computer has spent a huge amount of time stored in someone's laundry. It's full of lint, and it's got pretty severe corrosion. So step one is to wash the board down, step two is to remove the metal components that have started to rot - the RF modulator and the metal shield over the cartridge connector are first. It's vitals are better than some of the other dead ones in my stash though, so I feel confident that this little monkey will live again.

WelshWizard, sorry dude but with the state this thing's case is in, I'll probably use my spares case and keyboard on it. You're welcome to the keyboard from this one though, it only slightly looks like it'd give you hepatitis!

It might clean up OK yet.

I got excited after I cleaned the board up and decided to see what it would do after cleaning.



So I hooked it up where my breadbin normally lives and...



Jolly good! So it's now got pretty fantastic vital signs! I'm missing a blinking cursor and of course, it's unresponsive to keyboard input. Most likely cause of being left in the laundry cupboard? Failed CIA. This one will live again, oh yes.

Yes, it looks like it's getting there.

I wish I'd had more luck with my ProFile Lisa drive. I did some work on it tonight and for a moment thought I had solved the issue. But alas no. I''m starting to think it's a dry solder joint or bad socket on the controller board somewhere...the question is where? More sluething to be done in the next few days.

Anyway, well done on the Commodore. Good to see the pics. Yea, failed CIA I reckon. I blew a CIA chip on one of my Commodores once via static electricity.

Your C64 was certainly a sad state of affairs inside. At least you didn't have to fish mummified mice out of it like I did with one of my Apple clone units.

As it came from Christchurch it may have been ubder water for a while, who knows if you had cleaned it first it may have fired up fully the first time

It's degraded a bit since I've been working on it, looks like a bad PLA. Work will commence but hot damn these old ICs don't like to be relieved of their existing locations!

I have removed the old RF modulator, it was rotten inside and out. Board still has a bit of surface corrosion where it was located, but otherwise no major damage.

I argued with that PLA for three nights in a row. No dice, and I'm not wanting to apply too much more heat lest I really damage the board. So out of desperation I've ordered a desoldering station. Time will tell how it works out.

In the meantime, I decided it was time to hit the bodywork. I soaked the case parts in the laundry basin, in a weak solution of sugar soap. The only area causing concern was the rust damage in the bottom of the lower case, but that came away after a good scrub.



Case parts cleaned up. Definitely not in as such awful shape outside beyond its grime.



Cleaned the keyboard up too. Whole 64C body posing with the breadbin.

Well that's sort of a wrap until I get the PLA swapped and see what happens!

Case has cleaned up nicely. A retrobrite soak on a few of those keys might get rid of that yellowing.

Yes before I started trying to desolder ICs I practiced on a junk ISA card I had lying around. The first couple of ICs were disasters but I soon got the hang of it. I'd recommend to anyone starting off desoldering components to practice the technique on junk first. It's partly a black art.

tezza wrote:Yes before I started trying to desolder ICs I practiced on a junk ISA card I had lying around. The first couple of ICs were disasters but I soon got the hang of it. I'd recommend to anyone starting off desoldering components to practice the technique on junk first. It's partly a black art.

Solder wick or suction? I find a good quality solder wick does wonders - it's worth paying for a good one. If there's a large blob of solder I might use suction then solder wick.

I've been experimenting with both. The wick I'm using is Chemtronics stuff that I got from an electrical engineer buddy. It works, but is quite inconsistent - I suspect it's due to the age of the solder. I've tried applying some fresh solder which helped, but still not enough to get the solder from the vias. I've tried the old suction pump technique too, and either my pump is really really bad or my technique is horrible!

The desoldering station arrived today. So first I did some test runs on a failed Gigabyte Socket478 board I had kicking around at work, and was pleased with the results. So when I got home, I then did some trial runs on one of my other Commodore 64 boards before setting to the C64B3 that goes with my 64C. That PLA that had been giving me strife and I couldn't get out?



Bam! Out in about two minutes!

So now I just need to organize some sockets! Stoked!

Excellent,

What do these desoldering stations look like? Got a picture?

Ha! I just read the other thread where I see there is a pic! Great.